if (Posts.find().count() === 0) {
    Posts.insert({
        title: 'Baidu',
        url: 'www.baidu.com',
        flagged : false,
        author:'Wing'
    });
    Posts.insert({
        title: 'Bing',
        url: 'www.bing.com',
        flagged : false,
        author:'Chen'
    });
    Posts.insert({
        title: 'Google',
        url: 'www.google.com',
        flagged : false,
        author:'Feng'
    });
}
